Assessment of Potential Indicator Species for Monitoring ...

4b. Captive breeding possible and well understood?
Insufficient information.
5a. Is there historic information on contaminant burdens in the Fraser Basin?
No.
5b. Has this species been used in contaminant studies in other regions?
No.
5c. Have biological effects for this species been studied?
No.
GREAT BASIN SPADEFOOT TOAD Scaphiopus intermontanus
1a. Present in the Fraser Basin year-round?
Yes.
1b. Broad distribution?
No, only in the Okanagan and Nicola valleys and as far north as 70 Mile House in
the Cariboo region (Green and Campbell 1984).
1c. Common in Fraser Basin?
No, this species is threatened (Orchard 1984; Orchard 1992).
1e. Proportion of diet within the aquatic food web.
Diet of the adult is not well known although they are known to consume insects
(Orchard 1984). The tadpoles feed voraciously on anything organic including
algae, aquatic plants, dead fish, other tadpoles and even their own faeces (Green
and Campbell 1984).
2a. Has the home range of the species been described?
Has not been measured but they generally seem to be within calling distance of
spawning sites (2 km) (Orchard pers. comm 1994).
2b. Habitat selection is well documented?
Open woodlands, meadow, sage or bunchgrass prairie. It is unable to live in true
desert. Often found near permanent lakes or ponds but will range far afield to
higher elevations (Green and Campbell 1984).
2c. Breeding biology is well understood?
Breeds in early summer in temporary pools or the shallows of lakes when
conditions are adequate. These are alkaline or saline pothole lakes without fish
populations (Orchard 1992). Generally they will wait for a rain before breeding. The
males call in choruses (Green and Campbell 1984). Females lay their black eggs in
clumps in shallow water (Orchard pers. comm. 1994). The tadpoles transform in
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